Sustainable intensification in Tanzania: towards a better understanding of spatial variability of input responses to reduce farmer’s risks

Smallholder farmers constitute an important part of Tanzania’s agricultural economy contributing about 85% of maize produce (Suleiman and Kurt, 2015). The country’s national annual growth rate of maize is steadily rising at 4.6% in the last two and half decades and is the largest maize producer in East Africa (Barreiro-Hurle and J., 2012). However, maize yields are among the lowest in the Sub-Saharan Africa, fluctuating between 1.0 and 1.5 tonnes per hectare (Mbwaga and Massawe, 2002, FAOSTAT, 2015). Soil degradation constitutes one of the most limiting factors (Tenge et al., 2004, Mbaga-Semgalawe and Folmer, 2000) due to poor management practices. Agricultural land use without appropriate nutrient management results in ongoing reduction of soil fertility, leading to a poverty cycle (Tittonell and Giller, 2013). Tanzanian soils are often nutrient depleted and nutrients are more often yield limiting than water (Mowo et al., 2006). Targeted and efficient fertilizer use by improved nutrient management is key to increasing food production (Vanlauwe et al., 2011). There is still a poor understanding of the enormous variability in yield responses of various crops to fertilizer application. A wide range of factors may influence this response to fertilizer including management (sowing times, weed control), weather, soil constraints and effects of pests and diseases. A combination of proper fertilizer application with better management techniques is assumed to result in desired yield increment. This study will use UAVs to better understand spatial variability of input responses leading to improved fertilizer application advice combined with enhanced smallholder farming management practices for optimized maize yields in Tanzania.